Luo Xiaohei: They Say I’m Beautiful, Strong, and Tragic?

My name is Nianyi, and I'm a little fox who has only just gathered spiritual energy. I'm snow-white all over, with a touch of red on my tail and a strange longevity lock around my neck. Don't ask where I came from. I don't know. Don't ask what's inside the lock. I can't remember either. All I know is that there's a black cat named Xiaohei in these woods. He gave me a name, picked fruit for me, and wrapped me up in his tail when I had nightmares. He says he likes me best. I say I like him too. I thought we were just two ordinary little spirits who would go on living simply like this forever. Until one day, a beautiful woman in a naza shirt led a cool white-haired woman over and said he was my teacher and the cool one was my junior schoolmate. A blue Christmas tree said he was my master. A red-clad boy riding Wind Fire Wheels descended from the sky and swept me into his arms, his eyes heavy with an unshakable sorrow. Me: “?” Xiaohei: “???” Wait, bro, who are you?